This group has two primary directions. The first is to support all ongoing branch trials involving monoclonal antibodies used to treat cancer patients. Considerable effort has been focused on developing assays to support the clinical trial in which lung cancer patients will receive the monoclonal antibody directed against the autocrine growth factor, gastrin releasing peptide (GRP). These assays include a radiobinding assay to quantitate the amount of GRP expression by tumor tissue, a solid phase assay to measure monoclonal antibody levels directly as well as to measure the monoclonal's ability to bind free antigen. Other parameters to be measured include human anti-mouse antibody formation as well as endogenous formation of anti-idiotypic antibodies. The second effort of this group is to elucidate new peptides produced by lung cancer cells which share the autocrine stimulating property of GRP. Using a semi automated cell culture growth assay, fractions of conditioned media from selected lung cancer cell lines are analyzed for their impact of growth rate of lung cancer cells propagated in a defined media system. The goal being to generalize the strategy tested in the initial anti GRP monoclonal antibody trial, that is to control tumor growth by restricting access to essential growth factors.